TW512563B - Lightning arrester device for low-voltage network - Google Patents

Abstract

A lightning arrester device for protecting an electrical circuit against transient overvoltages, comprising at least one protective element consisting of a gas-type spark gap, which device comprises a set of gas-type spark gaps (2a-2c) connected in parallel and which individually have a surge current rating below a desired surge current rating.

Description

512563

512563 V. Description of the invention (2) The arc falling on the gap will be extinguished, which will not hurt the basic obedience of the gap, and the spark gap will be notified. Female —, Health (# state trip voltage, insulation voltage I ^ 化) When another instantaneous overvoltage occurs, it will not change: due to the function. On the other hand, if the surge current waveform = the surge current rating of the flower gap of the protection element, the dual element exceeds the arc damage element triggered by the fire gap ... this, ^: risk of falling on the spark width Rise, for example, will reach 300 to 700 volts or the de-voltage will be large. The instantaneous over-voltage amplitude will be lower than the new trip. ": If the two knives can complete the function of the protection element again, the arc will even: two = It should n’t be connected ... It is impossible to be in the case of over-power plant occurrence;;: Two-gap tripping state η ο η-trippingstate).…, The instantaneous overvoltage is a kind of occurrence time that is completely unpredictable, and the intensity is also predicted This is why when we want to increase the chance of the surge arrester device ^ I to withstand one and / or several consecutive moments of high instantaneous over-voltage, damage, it is sometimes necessary to use an enhanced surge rating. The reason for the arc capture device. A simple way to solve this problem is to use a gaseous spark gap that has a large surge current rating itself. Such gaseous spark gaps are available on the market. However The disadvantage of the spark-like gap is that its spark size is much larger than the spark gap with a smaller surge current rating described in the previous example, and the price is much more expensive. For comparison, the surge current rating is 20 kA, 8 / 2 0 # s or 5 kA, 1 〇 / 3 5 0 # s The spark gap consists of a cylindrical element with a diameter of about 8 millimeters (mm) and a length of 6 millimeters, and the surge current rating is 5 〇kA, 8 / 2〇〆s or 15 kA, 1 0/3 5 0 // s spark gap is determined by the diameter

Page 5 512563 V. Description of the invention (3) The same cylindrical element of 16 mm and a length of about 30 mm. In addition, the first type of spark gap mentioned above is manufactured in large quantities at a price of 1.5 francs each, while the second type of spark gap with a higher surge current rating is a special component manufactured in small quantities Each price is about 100 francs. Therefore, the purpose of the present invention is to provide a spark gap that can have an enhanced surge. To achieve this, according to the present invention, the set current ratings of a set of parallel gaseous spark gaps are lower than the required surge current. The energy flow (ie, the surge current rating) occurs when an instantaneous overvoltage occurs during a gas outbreak. With a clear distribution, their tripping voltages have the smallest tripping first when overvoltage occurs, and cause a short circuit across the endpoints. Generally this short circuit will have to wait for the flower gap caused by transient overvoltage. The spark gaps in parallel are inherently rated for surge currents. Yes Solve the problem of increasing the surge current rating. Although in principle this invention provides experiments that allow the intrinsically maximum discharge spark gap design of the capture device to prove an arc capture device that does not use bulky and expensive gaseous ratings. The bright arc capture device is an inclusive device, each with a surge current rating of the spark gap. The state spark gap does not increase the maximum discharge current value of the non-destructive f-parallel arrangement. In other words, the gas spark gap characteristics are often slightly different from each other. Therefore, when the instantaneous trip voltage of the gaseous spark gap will be across all other gaseous spark gaps to prevent other spark gaps from tripping, so all current flows through the only tripped fire. This is the same as individual spark gaps. As the method of the present invention, the surprising solution at first glance does not increase the value of the arc light capture current, but the applicant has done many things. Even so, the present invention can still improve the solitary light 512563 V. Description of the invention (4 ) The inrush current rating of the capture device. In particular, if we use a spark gap containing a refractory metal electrode, the electrode becomes open after the end of its life, even if an instantaneous overvoltage occurs and a surge current that exceeds the maximum discharge current allowed by each cremation gap, or even The spark gap triggered by the overvoltage is damaged by the overvoltage. The 5 melon light capture device made in accordance with the present invention can still be left without the overvoltage. The triggered spark gap continues to maintain the function of the protection element, as long as at least one of the spark gaps It should be intact. _ Alternatively, spark gaps made of fusible metal electrodes, preferably copper or copper alloys. This type of spark gap is used in the state of short-circuit I. In other words, if an instantaneous overvoltage occurs and a surge current exceeding the maximum discharge current allowed by each spark gap is generated, and the spark gap triggered by the overvoltage When damaged by overvoltage, its resistance becomes less than 1 ohm. The applicant's experiments on such spark gaps have shown unexpected phenomena. In the case of a high instantaneous overvoltage, after the spark gap with the minimum trip voltage is tripped, at least one adjacent spark gap is also tripped, but when the total number of spark gaps exceeds three, the spark gap does not change. Will all escape. This is very unexpected today, because the other spark gap short-circuited after the first spark gap tripped, and generally should prevent other spark gap trips. Although the cause of at least one other spark gap trip is not fully understood, we can imagine that the arc generated by the first spark gap that jumped off caused a strong magnetic field and / or a strong spark discharge, prompting the adjacent spark gap. Plasma is generated everywhere, which also promotes the escape of these spark gaps. In this case, the current surge generated by the overvoltage can flow through two to

The surge current of the two tripped gap currents is tripped according to the voltage network phase of the generator based on the gas fire voltage alone. Then the short-circuit current of the network (self-exti closed by other preventive actions is not tolerated to cause low-voltage large flowers. When the fixed value indicates the connected electrical flower gap, the fire circuit will flow, and notion Over-current system, and the circuit gap is' this effect is equivalent to dividing each tripped spark by two or three, thus enhancing the arc capture device.

The arc capture device is especially suitable for protection and low circuit. However, in this case, the arc capture device cannot be placed. Especially when the gaseous spark gap becomes arc-shaped when the transition gap occurs, it is equivalent to a semi-short-circuit-like spark current flowing in the gap, which is close to the net. The spark gap cannot be interrupted by self-extinguishing). In this case, the protective elements (circuit breakers, fuses, etc.) of the device will move. These two components are usually placed upstream of the device. This is because as long as the arc capture device is activated, it will be disabled. A known solution is to connect a spark gap in series with a component that can limit the short-circuit current mentioned above but can pass the transient current waveform. For example, these components can be composed of variable resistors, especially zinc-oxygen varistors. Yi

Therefore, when the arc light capture device designed according to the present invention is used to protect a low-voltage circuit, it can further include additional protection elements ~ a set of variable resistors connected in parallel with each other in series with the spark gap combination. The shunt varistors are designed so that the surge current is evenly distributed on each shunting branch. To do this, a solution is to use a varistor with a very close 1mA cutoff voltage, preferably in the range of plus or minus 1%, while the allowable range of varistors traditionally supplied is in the range of plus or minus 10%.

Page 8 512563 m

r Amendment No. 89123623 1 f / year Muhu 1 V. Description of the invention (6) It is best (actually well-known) that the variable resistor in this group of rheostats is connected to at least one thermal blocker. When one or more The connected varistor can start the visual signal transmission device when it is subjected to abnormal overheating. A specific embodiment of the present invention is that the varistor is paired in pairs, and each pair of varistor-resistor is combined with a thermal blocker. In addition, the combination of the thermal blocker uses a known method, that is, the use of a telemetry communication circuit capable of transmitting to a remote monitoring host to notify that at least one of the varistors combined with the spark gap is defective and needs to be replaced. The drawings are simply explained. By way of example, other features and advantages of the present invention will appear in the following detailed description of specific embodiments of the present invention. The related drawings are as follows: The multi-spark 1-gap arc light capture device designed by the invention represents the situation when a current with an intensity exceeding the rated value of the gaseous spark gap surge current flows through the cremation gap constituting the arc light capture device and after the current flows; FIG. 3 is a longitudinal sectional view of a spark gap that can be used in an arc light capture device according to the present invention; FIG. 3 is a more detailed electronic diagram of two arc light capture devices for protecting a low voltage network according to the present invention; FIG. 4 shows FIG. 3 Another specific embodiment. First referring to FIG. 1, the arc capture device 1 according to the present invention is basically composed of several gaseous spark gaps, for example, three gaseous spark gaps 2, 2, and _ 2 g, connected in parallel between nodes 3 and 4. Node 3 is used to connect to the circuit to be protected (phase or neutral point); node 4 is used to connect to the ground, preferably through a current limiting element, which will be detailed later, see Figure 3.

O: \ 67 \ 67163-910903.ptc Page 9 512563 Amendment No. 89123623 V. Description of the invention (7) Each of the three gaseous spark gaps 2 and 2 has a structure similar to the spark gap 2 shown in FIG. 2. The spark gap 2 is composed of a ceramic tube 21 with a size of, for example, an external diameter of 8 mm and a length of about 6 mm. The middle is filled with a rare gas. The end of the ceramic tube 21 is sealed with dish-shaped conductive metals 22 and 23, and is used as a contact when the spark gap is used. The end of the ceramic tube 21 is treated with metal. For example, the dish-shaped conductive metals 22 and 23 can be consolidated with the ceramic tube 21 by welding. The two disk-shaped electrodes 24 and 25 are respectively fixed to the dish-shaped conductive metals 22 and 23 by welding on their inner faces. The two disk-shaped electrodes 24 and 25 are arranged face to face at a predetermined interval, and the size of the interval determines the value of the spark gap trip voltage. In order to help escape, it is better to lengthen some graphite wires 26, 27 on the cylindrical inner wall surface of the ceramic tube 21, the graphite wires 26 and the dish-shaped conductive metal 2 3 have electrical contacts, and the graphite wires 27 and the dish-shaped metal 2 2 with electrical contacts. The disc-shaped electrodes 24 and 25 may be made of a refractory metal, such as tungsten, in which case the spark gap 2 will usually become an open circuit at the end (the trip voltage becomes very high). They can also be made of fusible metals, such as copper or copper alloys, in which case the spark gap 2 usually ends up short-circuited (resistance less than 1 ohm). If the circuit or electronic equipment protected by transient overvoltage is operated at 230 volts AC supply voltage, the gaseous spark gap is 2§, 2 stones, and the applicable AC trip voltage is about 300 volts, and the surge current rating is 20 kA, 8/20 // s or 5 k A, 1 0/3 5 0 // s spark gap. Of course, the invention is not limited to these values. Therefore, especially if the circuit to be protected operates at a higher voltage of ¢ 1. If it is 400 volts, then the spark gap can choose a spark gap with a higher trip voltage, such as 500 volts. The invention is also not limited to arc capture devices using three parallel spark gaps.

O: \ 67 \ 67163-910903.ptc Page 10 512563 _Case No. 89123623 f / year f month S Revision_ V. Description of the invention (8). More precisely, we want to have several spark gaps for the arc capture device, the number is limited only by the maximum volume and / or the highest cost of the arc capture device fixed in advance. In fact, the number of spark gaps is limited by not exceeding the unit cost of spark gaps with higher surge current ratings, or if we can afford to use several spark gaps with higher surge ratings. Let the cost be several times higher than the above unit cost. If we use a spark gap with a refractory electrode on the arc light capture device of the present invention, if the value of the instantaneous overvoltage is greater than the trip voltage of the spark gap, as shown in the figure, the gaseous spark gap will be the first to trip. . The first trip-the spark gap is usually the one with the lowest dynamic trip voltage. Therefore, the other two gaseous spark gaps 2 b and 2 c will be short because of the gaseous spark gap 2 a that has escaped, and they cannot escape anymore. Therefore, the discharge current stomach caused by all the surge currents will only interact with each other through the gaseous spark gap 2, and the other two gaseous spark gaps 2 will remain unchanged. If the mutual current waveforms passing through the gaseous spark gap 2 have characteristics lower than the surge rating of the spark gap, the basic characteristics of the latter (static trip voltage, insulation resistance, etc.) will not change, and the arc capture device can also be maintained Full inrush current rating capability. On the other hand, if the intensity of the surge current across the gaseous spark gap 2 is greater than the maximum discharge current of the spark gap, the basic characteristics of the latter will change, especially its trip voltage will rise sharply, if it exceeds the spark significantly The rated characteristic of the surge circuit of the gap, this spark gap will definitely enter an unbreakable condition and become an open circuit. This situation is the same as cutting off a defective gaseous spark gap 2 once, as shown in Fig. 1. In the arc capture device of the present invention, two gaseous spark gaps 2k and 2k are connected in parallel. But this does not affect its basic characteristics

O: \ 67 \ 67163-910903.ptc Page 11 512563 Case No. 89123623 Amendment V. Description of Invention (9), because if an overvoltage occurs again, and the intensity is greater than the remaining gaseous spark gap, it is one of the benefits. Surge current with a surge current rating. It can still withstand at least one surge current and complete the task of a protective device. Based on this reasoning, we can say that the arc light capture device designed according to the present invention has a larger surge current rating than a single spark gap in its composition. If the number of spark gaps of the arc capture device designed according to the present invention is η, the acceptable number of surges (without damage) is η-1 〇 Now referring to FIG. 3, we can still see three Gaseous spark gaps of each group are connected in parallel, node 3 is connected to the supply network line L (phase or neutral point), and the other connected node 4 is connected to ground. Between a group of three gas spark gaps 2 den-and node 4, a group of rheostats 5 den-5 f are inserted in series with each other, such as a zinc oxygen rheostat. Six rheostats are provided in the proposed example, but this number is not a limitation of the present invention. In fact, the total number of varistor can be selected to achieve a given discharge current and / or a specific backup number in case one or more varistor is defective. Rheostats 5 are best paired with each other: 5 and 5 each other, 5 deniers, and 5 each other. Each pair is respectively connected with a thermal blocker 6d, 6b and spit. If any of the varistor pairs corresponding to the gaseous spark gap 2§- is subjected to abnormal overheating, the varistor pair can be cut off. This can happen, especially when the varistor is nearing its end of life. In this case, it is necessary to cut off the defective varistor or varistor, because they may explode suddenly, causing damage to nearby components (just the same as sparks using heat-resistant electrodes).

O: \ 67 \ 67163-910903.ptc Page 12 512563 Amendment No. 89123623 V. Description of the invention (10) The gap is only open for Wit without causing damage). Each of the three thermal blockers 6 deniers, 6 daggers, and 62 only corresponds to a corresponding varistor pair in terms of heat: 5 is connected with, 5p and 5 are connected together, and 5 beans are connected with 7 denier in the figure with a dotted line , Said. In addition, each of the thermal blockers 6 and 6b can activate a visual signal transmission device 8 and ㊇, which are indicated by dashed lines 9 and 9 and 9 £ respectively in the figure. Each pair of rheostats, such as 5 deniers, 5 male pairs, and connected to the rheostat pair. The thermal blocker and the visual signal sending device, such as the thermal blocker 6 denier and the visual signal sending device 8, can be replaced by a similar French Patent application FR- 2 7 6 1 54 3 · Module composition. In addition, each of the thermal blockers 6, 6 and 6 is designed to be able to operate on the micro contact 10, which is indicated by a dashed line 11 in the figure, so that when the thermal blockers 互 6 and 6, One of them can change the state of the micro contact 10 when one of them is defective due to the defect of one of the 5 resistors and 5 masters. The micro contact 10 is connected between the two nodes 12 and 13 and then connected to a telemetry signal line 14 such as a remote monitoring station. Therefore, when the state of the micro contact is changed, it is possible to notify the operator at a distance that one of the thermal blockers 6 and 6 has been affected by the defect of one of the rheostats 5 and 5f. In addition to the advantages mentioned above, the other advantages of this arrangement are as follows: a) The leakage current of the arc capture device can be almost completely eliminated by high insulation resistance and a smaller amount of gaseous spark gap rating; b) To a certain extent, the maximum || nominal operating voltage (usually referred to as U c) of the protection circuit of the arc capture device to be affected without affecting the degree of protection (usually referred to as U p), that is, the current flow caused by the transient overvoltage The voltage actually experienced by the circuit when the arc light capture device is crossed. Especially U c is caused by spark gap

O: \ 67 \ 67163-910903.ptc Page 13 512563 Amendment No. 89123623 V. Description of invention (11) The static trip voltage is determined, and U p is determined by the residual voltage of the rheostat. This feature makes the arc capture device suitable for unstable and fluctuating circuit networks. The specific embodiment of FIG. 3 pre-pairs the varistors 5 to each other, and each pair of varistor · s is connected to a thermal blocker 6 d, 6 d, and 6 g, respectively. The thermal blockers are configured to be independent and can start a visual signal transmitting device 8 mutual. However, the present invention is not limited to such a configuration. In particular, as shown in FIG. 4, a simpler configuration can also be adopted, in which all the varistors 5 to 5i are connected to a single thermal blocker 6, which is indicated by a dotted line 7 in the figure. The next step is to provide a single visual signal transmitting device 8 which is connected to the thermal blocker 6 through the link 9. The other parts of FIG. 4 are the same as those of FIG. 3 and will not be described in detail here. For example, when 2a to this type of gaseous spark gap is used, and a fusible electrode is used so that the final spark gap is used in an open circuit state, the configuration proposed in FIG. 4 is quite suitable. In this case, if an instantaneous overvoltage with a larger amplitude than the spark gap trip voltage occurs and the value of the surge current is not large, all discharge currents will pass through the spark gap with the smallest dynamic trip voltage without changing the spark gap. The basic characteristics are the same as when using spark gaps with refractory electrodes. If the magnitude of the surge current is large, the spark gap with the weakest π will jump off first, and then the two sparks adjacent to the spark gap with the weakest π will jump off almost at the same time. Therefore, the value of the discharge current (denoted as Isurge) flowing through each spark gap that is tripped is approximately divided by two to three. If the value of Isurge / 2 or I sur rg e / 3 is appropriate, and is lower than the maximum discharge current (represented as Imax) allowed for each spark gap that is tripped, the latter will not be damaged, and if a transient overvoltage occurs later on , Lightning arrester can still work.

O: \ 67 \ 67163-910903.ptc Page 14 512563 _Case No. 89123623 f 3 amended_ V. Description of the invention (12) On the other hand, if the surge current amplitude is extremely large (Isurge / 2 or I surge / 3 > I ma X), at least one tripped spark gap will be short-circuited and will continue to be maintained after the surge current passes. This will end the life of the arc capture device. Especially in this case, the life of the spark gap ends and is maintained in a short-circuit state, so the life of the entire circuit is also terminated, both conditions can be borrowed. The visual signal transmission device 8 (Figure 4) and the telemetry signal line 14 (if (If any) communicate the message clearly. In particular, in the case of the parallel gaseous spark gap network 2 mutual,. 2b, the surge current rating is lower than that of the rheostat network 5 mutual, if one of the spark gaps is maintained at-short circuit by excessive surge current In the state, the rheostats 5 to 5i will directly receive the voltage of the circuit network. Since this voltage is greater than the operating voltage of the rheostat, the latter will operate in a permanent chopping mode for a few seconds and then generate a lot of heat. This has the effect of triggering the thermal blocker 6, and then cuts off the circuit (and therefore interrupts the fault current) and activates the visual signal transmission device 8 and the micro contact 10 connected to the telemetry signal line 14. Of course, the above-mentioned specific embodiment of the present invention is very simple and is only an indication, and those skilled in the art can make many modifications without departing from the scope of the present invention. Therefore, in particular, the number of spark gaps can be less (but at least two) or more than in the examples shown in Figs. La, 3, and 4. Supplementary notes (1) Refractory metal means that the metal can withstand very high temperatures without melting, for example, higher than 2 500 ° C. Fusible metals represent metals that melt at lower temperatures, such as below 15 0 ° C. Refer to lines 2 to 8 on page 7. When using electrodes in refractory metal, the spark gap becomes open after the end of life. Similarly, having

O: \ 67 \ 67163-910903.ptc Page 15 512563 Amendment No. 89123623 V. Description of the invention (13) The spark gaps of the electrodes in refractory metal will jump out one by one at a time. Therefore, the maximum surge current is not modified by several parallel connections having spark gaps to the electrodes in the molten metal. However, once a spark gap with electrodes in a refractory metal is dead, it is equivalent to being disconnected from the spark gap, and the lightning arrester remains in operation as long as at least one of the spark gaps is intact.

Refer to page 7, line 9 to page 8, line 3, when using fusible metal electrodes, the spark gap will eventually become short-circuited when used. Similarly, the tripping of a spark gap with an electrode in a fusible metal can cause the spark gap of at least one adjacent electrode with a fusible metal to escape, possibly through electromagnetic coupling (p. 7 from 20 to 20). 2 4 lines). Therefore, a parallel connection of several spark gaps with electrodes in a fusible metal will increase the maximum undulating current of the device by a factor of two or more (page 7, line 24 to page 8, line 3). However, due to the end of the spark gap with the electrode in the soluble metal, it is equivalent to a short-circuit condition, which can cause the device to be damaged (pages 15 to 16 on page 15). When durability of the device is a priority, refractory metals are preferred. When the device's high inrush current rate is a priority requirement, it is best to use easy metal). (II) Leakage current description As explained on lines 4 to 8 on page 4, the operation of the gaseous spark gap is similar to that of an electronic switch. The spark gap is almost equal to the open circuit state, as long as the voltage applied to the spark gap is lower than the trip voltage of the spark gap (see lines 4 to 5). In this state, the spark gap is called "extinguished". However, even in the extinguished state, the spark gap is not exactly equal to the open circuit

O: \ 67 \ 67163-910903.ptc Page 16 512563 Case No. 89123623 Revision V. Description of Invention (14) Status. In other words, the spark gap, although very large, has a limited insulation resistance (see "almost considered infinite" on lines 4 to 5 on page 4) and has a certain amount (page 13 on line 21) . Therefore, when a DC or AC voltage lower than the spark gap trip voltage is used, the spark gap will be crossed by a certain current, which is called “leakage current”. Lines 13 to 20 on page 13 indicate that parallel connection of several spark gaps can help reduce leakage current compared to the use of spark gaps with high surge current rates (lines 17 to 19 on page 5) because Description of higher resistance and lower capacitance 0 (C) Self-extinguishing

As explained on lines 5 to 8 of the fourth page of the specification, when the voltage for the spark gap reaches the trip voltage of the spark gap, the spark gap becomes as conductive as the short circuit state. In this state, the spark gap is called "tripped" (see line 1 on page 8). In this trip state, which is also called “arc-like” (page 8, line 7), the spark gap is crossed by a large discharge current (see page 4, line 8). "Self-extinguishing" is the reverse change of the state of the spark gap, and it changes from a tripped state to an extinguished state. As long as the discharge current is above a certain threshold (t h r e s h ο 1 d), the spark gap is still tripped. As long as the complete voltage of the network is used for the spark gap, self-extinguishing cannot be obtained. This is illustrated on page 8 on lines 6 to 10.

(4) Residual voltage descriptions Page 13 on line 22 to line 14 on line 4 is the case where the spark gap is connected in series with the varistor between the circuit and the ground (line 23). In this case, the voltage of the circuit is equal to the voltage of the spark gap plus the

O: \ 67 \ 67163-910903.ptc Page 17 512563 Amendment No. 89123623 V. Description of the invention (15) Voltage. When the spark gap is tripped, the spark gap is almost equal to the short circuit state, where the varistor has a large resistance. Therefore, the voltage of the spark gap is much smaller than the voltage of the varistor, which is called the “residual voltage” of the varistor. In other words, when the spark gap is tripped, the voltage across the spark gap is almost -zero, but there is still a substantial voltage through the rheostat. (E) Explanation of the cut-off voltage. In the case of lines 22 to 23 on page 8, the voltage at 1 mA DC test current is called the 1 mA cut-off voltage. This quantity is generally used to specify a rheostat. A varistor is an electronic component with a resistance, which depends on the voltage function used. Below a certain voltage, the resistance is high, for example about 10 million ohms. Above the threshold, when the varistor experiences an over-voltage, the resistance will almost drop to the micro U ohm, which is generally small, so that the current across the varistor will increase significantly. As a result, the voltage of the varistor will be greatly relaxed to a normal voltage, which is called the cut-off voltage of the varistor. (6) Explanation of permanent clipping mode The clipping mode is the state of a varistor with reduced resistance, so that the varistor can cut off the overvoltage. If the overvoltage is a transient phenomenon, the varistor is generally not damaged by this type of overvoltage and will recover its high resistance after the overvoltage disappears. In this case, the clipping mode is temporary. The situation on lines 15 to 9 on page 15 is the opposite, where the overvoltage is the voltage from the network (see line 12 on page 15). As long as the network is not shut down, this type of overvoltage will last for a long time and can be called permanent. Therefore, the rheostat is switched permanently to the clipped mode.

O: \ 67 \ 67163-910903.ptc page 18 512563 case number 89123623 month

J: Modified drawing, simple description, component symbol description 1 2 2 a-2 c 3 4 5 a to 5 f 6 6 a, 6b, 6 c 7 7a, 7b, 7c 8 8 a, 8b, 8 c 9 9 a, 9b, 9 c 10 11 12 13 14 21 22 24 26 arc light capture device spark gap gaseous spark gap node node rheostat thermal blocker thermal block line dashed line visual signal sending device visual signal sending device connected to dotted micro contact dotted line node node Telemetry signal line ceramic tube 2 3 dish-shaped conductive metal 2 5 disc-shaped electrode 2 7 graphite wire dish-shaped conductive metal disc electrode graphite wire

O: \ 67 \ 67163-910903.ptc Page 19

Claims (1)

512563 _ Case No. 89123623 f / year ^ month j said amendment _ _ / /--6. Application for patent scope 1. An arc light capture device for protecting a circuit connected to a low voltage network from transient overvoltage damage, including at least one A protection element composed of a gaseous spark gap. The element includes a set of gaseous spark gaps (2 denier to 2 ^) connected in parallel, each of which has its own surge current rating, which are all lower than the required surge current. Rating. 2. The arc light capture device according to item 1 of the scope of patent application, wherein each spark gap (2) is composed of a small ceramic tube (2 1) with a rare gas in the middle, and the end of the ceramic tube is made of a dish-shaped conductive metal (22 It is sealed with 23) to make contacts, and the inner surfaces of the two disc-shaped electrodes (24 and 25) are fixed with the dish-shaped conductive metal (2 2 and 2 3), respectively, and arranged oppositely at a predetermined interval. 3. For the arc light capture device in the second item of the patent application, the disc electrodes (24 and 25) are made of refractory metal, preferably tungsten. 4. For the arc light capture device in the scope of patent application item 2, the disc electrodes (24 and 25) are made of refractory metal, preferably copper or copper alloy. 5. The arc light capture device according to any one of claims 1 to 4, which is used for a low voltage circuit, and further includes a group connected in series with the gaseous spark gap group (2 denier-2g) in parallel with each other. Rheostat (5 mutual-5f) as protection element. 6. The arc light capture device according to item 5 of the scope of patent application, wherein the group of varistor (the varistor in the 5-generation combination is connected to at least one thermal blocker (6 denier-6g)), which can be placed in the varistor (5 mutual-5) One is to start at least one visual signal transmitting device (8 to -8ρ) when it is subjected to abnormal overheating. 7. For example, the arc light capture device in the scope of patent application item 6, wherein the rheostats (5 denier-5i) are paired in pairs (5 mutual- , 5g-5Q, 5§-5 to), thermal blocker (6a O: \ 67 \ 67163-910903.ptc Page 20 512563 Amendment No. 89123623 6. The scope of patent application (6 乜, 6p) is connected to each pair of rheostat separately. 8. For example, the arc light capture device under the scope of patent application No. 7, wherein the thermal blocker (6 deniers, 6 cubits, 6 £) is connected to the telemetry signal line (1 4). 9. For example, the arc light capture device in the scope of patent application No. 5 in which the varistors (5 deniers, 5i) in parallel with each other have similar 1 milliampere cutoff voltage values, preferably within plus or minus 1%. < 1 O: \ 67 \ 67163-910903.ptc Page 21